Microsoft Fixes XML Flaw as Attackers Circle in Patch Tuesday Update

Microsoft plugged a number of security holes today impacting Windows, Internet Explorer and other products as part of its monthly security update.

Microsoft released patches for 16 security vulnerabilities today, including a bug affecting Microsoft XML Core Services that is being exploited in the wild.

The patches are spread out across nine bulletins, three of which are rated €œcritical.€ Among those critical vulnerabilities is a remote-code-execution issue impacting XML Core Services 3.0, 4.0 and 6.0 on all supported versions of Windows that could be exploited via drive-by attacks.

€œThe most important patch this month is undoubtedly the XML core services bug," said Andrew Storms, director of security operations at nCircle. "Microsoft issued an advisory for this bug in early June and we've already seen the exploit in a number of exploit toolkits and attacks have been reported in the wild."

"If you are paying close attention, you'll notice that the XML version 5 patch for the bug isn't shipping today," he added. "The fix for this version is probably not ready yet, so Microsoft decided to deliver the other patches. So far, all the attacks in the wild utilize XML version 3, so this release, even though not totally complete, seems like a no-brainer."

The update also included a critical patch for Internet Explorer 9, the latest version of Microsoft's popular browser. The IE9 bulletin, MS12-044, swats two security bugs that can be exploited to remotely execute code. Neither issue is known to be getting targeted in the wild, Microsoft said.

"The vulnerabilities could allow remote-code execution if a user views a specially crafted Web page using Internet Explorer," according to Microsoft's advisory. "An attacker who successfully exploited any of these vulnerabilities could gain the same user rights as the current user. Users whose accounts are configured to have fewer user rights on the system could be less impacted than users who operate with administrative user rights."

"Apply this patch as quickly as possible if you run IE9. The exploitability index is 1, meaning that Microsoft believes that it is easy for attackers to reverse-engineer the patch and develop an exploit," blogged Wolfgang Kandek, chief technology officer of Qualys. "What makes MS12-044 more interesting is that it's the product of an accelerated update cycle that Microsoft has been working on. In the past, Internet Explorer was updated only every two months€”that was how long it took to get through all the compatibility testing required for a stable release. Now, Microsoft has streamlined this process to reduce the time needed by 50 percent."

The final critical bulletin, MS12-045, addresses a vulnerability in Microsoft Windows that, like the other critical bugs, can be exploited to remotely execute code. According to Microsoft, the vulnerability exists in the way that Microsoft Data Access Components accesses an object in memory that has been improperly initialized.

The remaining bulletins for this month impact Microsoft Office, Windows, Microsoft Server Software and Microsoft Developer Tools. Microsoft classified each of those six bulletins as €œimportant.€

In addition to the patches, Microsoft released Security Advisory 2719662, which allows system administrators to disable the Windows Sidebar and Gadgets on supported versions of Windows Vista and Windows 7 with one Fix-it click.

"As many of you are aware, Windows 8 will deprecate the Sidebar and Gadgets, and Gadget developers are already shifting their efforts to the online Windows Store," blogged Yunsun Wee of Microsoft's Trustworthy Computing group. "Meanwhile, we€™ve discovered that some Vista and Win7 gadgets don€™t adhere to secure-coding practices and should be regarded as causing risk to the systems on which they€™re run."

The company also issued Security Advisory 2728973, which places certain digital certificates in the Untrusted Certificate Store.

"Though we have no indication that those had been compromised or misused in any fashion, as a precautionary measure we€™ve revoked them," Wee blogged. "A subset of those was in addition found to have code signing permissions, which has earned them a place in the Untrusted Certificate Store."